Well-drilling tool.



J. PERRIER.

WELL DRLLLING TOOL. y APPucAnoN FILED Nov. 1o. 19m.

Patented Apr, 19m 1 was llO

WELL-pauline Toon anstatt.

Specification of Letters Patent.

latented'Apr. 25. will@ I Application filed November 10, 1915. Serial No. 66,785.

To all whom 't may concern:

Be it known that I, JAMES FERMER, a subject of the King of Great Britain and Ireland, &c., residing at Surat, in the State of Queensland, Commonwealth of Australia, have invented certain new and useful Improvements in and Relating to Tell-Drilling Tools; and I do hereby declare the following to be a full, clear, tion of the invention, such as will enable others skilled in the art to which it appertains tomake and use the same.

This invention relates to percussive well drilling tools, especially the drilling bit under the sinker'bar, t'o which also this invention can be applied.

Drilling tools vibrate when jumped in a deep bore, and are apt to break the sides of the hole and causeqthe direction of the bore to depart from the vertical. To improve. its trueness the'bore is, according to knownI methods, subsequently dressed by a reamer having a body of relatively large diameter. But by my invention I save time by producing a satisfactory bore in one operation; that is, a straighter bore, and it is drilled faster.

Another feature of known methods is that the drilling bit rotates somewhat to strike the bottom in a new place at many of its impacts; The suspending cable connects with a swivel' which permits the cable and connected tools to yield easily to any rotative iniiuence. There is a natural tendency to rotation due to the cable very slightly stretching and untwisting its strands, owing to the weight ofthe suspended vtools and its own length, as the bit descends, and then a reaction occurs, the cable twisting in the contrary direction (but not necessarily to the same extent) upon the bit reaching the bore bottom, or as it is raised. The directions of such automatic rotation depend on the direction of twist of the strands, and whenever the rotation one way is unequal to that in the reverse direction the successive impacts on the bore bqttom will be in dierent positions (in plan View) but will frequently be much less than 20 degrees away Yfrom one Aanother and some of the successive blows will occur at about the same place. The latter is a disadvantage which makes drilling slow and diflicult, and which my invention avoids. I so vary the rotative effects that the angle between successive impacts may approximate generally to a third or half of a right angle,

and` erect descripy but in any case there will be much less likelihood of successive impacts coming in the same place.

In applying my invention,y the drilling bit, a sinker bar, or the like is made of special form, and is given any length of stroke suitving the geological formation. Known means exist to regulate the speed oi the drilling bit, and for my purposes the speed of dropping' it should differ from the speed of raising it, as by being faster; the extent of rotation during the drop will then diil'er more certainly from the extent of reverse rotation while the bit is being raised, that is any tendency of the rotation to be equal each way is obviated. 1.

The drilling bits .I use have bases with edges of any known kind, and I use flat sides to allow of easy resharpening or dressing when required. The cutting edge is slightly wider than the bit body which instead of being an ordinary `flat bar, is a bar with a longitudinal twist of slow pitch, and small extent, comprising for example, less than one revolution. My improved tools will in practice be provided in sets of different dimensionsv to allow drillmen to select to suit their work.

To augment the rotative effect any sinker bar or the like above thefbit may have a similar longitudinal twist but as ordinary sinker bars are of small diameter relatively to that of the bore, atwist in an ordinary bar would have little rotative e'ect; therefore I use bars of enlarged diameter, though not so largeas to jam in the bore. i

In the drawings herewith simple embodiments of this invention are illustrated.

Figure l shows my improved bit; and Fig. 2 shows this bit on a smaller scale at- .tached to my improved sinker bar.

a is a cutting edge at the bit base. 7i is the lower end of the bit, slightly wider than the bit body e. The lower part has in my preferred form ,flat surfaces whichlOO allow of easy resharpening.

c is any wrench squared upper end of the bit, and cl any suitable coupling thread. p

The important part as to this invention is the body e between the bit ends. This body has a longitudinal twist, and its width is suiciently great to enable the twist to be effective in causing orassisting to cause by friction with the air or any matter in the bore partial rotation ofthe bit in one direc tion when it rises and in tion when it drops.

the reverse direc- 4 ing end connecting means, as screw thread g. The directions of twist of the parts e lillibe the direction and f, or like tools, w

of twist of the cable strands, so that as the cable rotates in descending the rotation is augmented by the twist in the said tool or tools. g

As those skilled in well sinking know, bits and sinker bars are' used'with `drilling jars and so forth connected between them and the cable which is reciprocated. Sometimes water is fed into the bore. the tools used being adapted to allow of water reaching the bottom. I may also use water. and drill jars.4

Various known boring tools have twisted bodies not for the purpose of my invention, but, by rotation under force, to cause penetration without reciprocation.

Having described this invention what is claimed by `Letters latent iszl. In an apparatus for bore drilling by percussion, an elongated tool having a wide body thin in cross section and twisted from a point substantiallyT adjacent its cutting edge to a point substantially adjacent its upper end, the cutting edge of the tool being wider than the twisted body, whereby the sides and edges ot' said twisted portion will be free of contact with adjacent parts of the apparatus and the walls ot' the bore, the twisted portion of the body in its movement acting against the air or any matter in the well, causing rotation of the tool as the latter rises and falls.

2. In an apparatus for bore drilling by edge to a point substantially adjacent its upper end, a sinker bar having a wide body thin in cross section and connected to the tool and provided with a twist corresponding to the twist ot' the tool, the twist in the sinker bar extending substantially throughout its entire length, the cutting edge of the tool being wider than the twisted body, whereby the edges oi the twisted portions lof the tool and the sinker bar will be free of contactwith adjacent parts ot the apparatus and the walls of the bore, the twisted portions ot' the tool and the sinker bar when the latter are raised and lowered being acted on by the air or other matter in the bore wil cause rotation of said tool and sinker bar.

3. In an apparatus for bore drilling by percussion, an elongated tool having a wide body of less width than the width of the cutting edge, said body being thin in cross section and twisted substantially throughout its length, the body of the tool being of less width than the cutting edge the sides and edges ot' said twisted portion will be tree of contact with adjacent parts of the apparatus and the walls of the bore when the tool is in operation, thev twisted portion ot' the body in its movement acting against the air or any matter in the well, causing rotation of the tool as the latter rises and falls.

-In witness whereof I have hereunto set my hand.

JAMES FERRER. 

